Patents by Inventor Toshiki Hirao

Toshiki Hirao has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4739202
    Abstract: A rotor for a superconducting electric rotary machine comprises a coil supporting tube, a superconducting wire constituting a superconducting field coil, in-line insulators disposed between the laterally adjacent lines of the wound wire and layer insulators between the vertically adjacent layers of the wound wire of the coil, wherein at least one of the line insulators and the layer insulators is formed by a grooved insulating material or a perforated insulating material.
    Type: Grant
    Filed: February 2, 1987
    Date of Patent: April 19, 1988
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Hidenao Hatanaka, Akinori Ueda, Toshiki Hirao, Susumu Maeda, Kouichi Ooshita, Mitsuhiro Uchida
  • Patent number: 4649303
    Abstract: A rotor for a superconducting rotating electric machine of the type having a coil-carrying shaft including torque tubes connected to opposite ends thereof. A circumferentially-extending groove is formed in the coil-carrying shaft between one of the torque tubes and a recess in the coil-carrying shaft in which superconducting field coils are housed. The radially outer end of the groove opens into a space for liquid helium provided between the outer surface of the coil-carrying shaft and a helium-sealing outer tube. Heat entering the coil-carrying shaft and conducted in a path along the torque tubes is absorbed by the liquid helium within the groove and is prevented from reaching the superconducting field coils. The radially inner end of the groove can be sealed, or it can be connected to a central cavity of the coil-carrying shaft by one or more radially-extending holes through which liquid helium can flow for improving the circulation of helium through the coil-carrying shaft.
    Type: Grant
    Filed: January 10, 1986
    Date of Patent: March 10, 1987
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Toshiki Hirao
  • Patent number: 4475052
    Abstract: The present invention is an air gap winding rotating electric machine in which the stator coils are disposed between the stator side magnetic shield and a thin-walled electrically insulating cylinder which surrounds the rotor. The stator coils are prevented from lateral movement by electrically insulating members inserted between adjacent sets of stator coils. In presently existing air gap winding rotating electric machines, these insulating members fit into slots in the magnetic shield; they are difficult to install and frequently become loose, resulting in the loosening of and possibly damage to the stator coils. In the present invention, the magnetic shield has inward projections instead of slots, and insulating members are secured by the use of taper keys, with the result that installation of the insulating members is easy and there is less chance of their coming loose than in presently existing machines, resulting in a more reliable installation of the stator coils.
    Type: Grant
    Filed: March 4, 1983
    Date of Patent: October 2, 1984
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Kouichi Okamoto, Toshiki Hirao, Tatsuei Nomura
  • Patent number: 4443722
    Abstract: Described is a rotor of a superconductive rotary electric machine in which laminated coil protective covers composed of a plurality of thin-walled cylindrical plates are placed between both end parts of the superconducting field coils and coil holding rings that are mounted at both ends of a coil mounting shaft.
    Type: Grant
    Filed: June 8, 1982
    Date of Patent: April 17, 1984
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Toshiki Hirao, Kouichi Okamoto